Afghan policemen keep watch at a check post near the U.S. Embassy in Kabul on June, 26. 2013. (Shah Marai/AFP/Getty Images)

Since the State Department awarded contracts to expand the U.S. Embassy in Kabul, Afghanistan, the price has grown 24 percent and is running two years behind schedule, according to the Government Accountability Office.

It’s up to $774 million from $625 million for the expansion, under contracts awarded in 2009 and 2010. The main reason was changed construction costs, including on the size of buildings and security upgrades. There was also an expansion in the number of desks and beds required, as U.S. direct hires for the facility jumped from 320 to more than 1,000.

And it’s not clear whether the costs will continue to increase.

“Uncertain political and security environment makes it difficult to determine whether current projects and existing facilities will meet future embassy needs,” the presentation for Hill staff released to the public Tuesday states. “Long-term construction has been occurring in an unpredictable political and security environment characterized by dramatic changes in U.S. staff levels.”

A House report recently indicated Congress’ concerns about spiraling embassy costs, which might result in new reporting requirements to the Hill.